Both oven displays inadvertently display Comm Error with 800 phone number. Happens during preheat or cooking. Ovens turn off, breaker NOT tripped. 3 new boards and the electronics interference piece have been installed. Still happens. When both knobs are turned to off and breaker is turned off, then on, oven works again, until it happens again. Thermador has been no help. Being told it’s “electronics interference”. We use cell phones, no other hi tech electronics around here! Have had several repair guys here, all baffled. PLEASE HELP!